And while Nairn is in the dark when it comes to Hodor’s past, he’s got plenty of theories.

He revealed: ‘There is no way Hodor is simple beneath it all. I truly believe that, and can’t wait to find out. I do have a couple of favourite theories, but I’ve decided not to voice them anymore, as I don’t want [author] George [R.R. Martin] to see them and think “Hell, no!”’

Asked whether he knew Hodor would be a fan favourite from the off, he told WinterIsComing.net: ‘I never dreamed things would have turned out how they have. Things seem to keep happening that I constantly have to check myself and think “Really? Is this real?”

‘I knew Hodor would be a popular character… D&D [David Benioff and Dan Weiss] told me he would, but I didn’t think to the level he has so far! I love the guy, I can see why people like him.’

Game Of Thrones season 4 kicks off on April 7 at 10pm on Sky Atlantic.